Calcium modulation of single SR potassium channel currents in heart muscle.
A. Uehara, M. Yasukochi, and I. Imanaga.
J. Mol. Cell. Cardiol. 26 (2): 195--202 (February 1994)

The modulating effects of Ca$^2+$ on single K$^+$ channel currents in canine heart sarcoplasmic reticulum were studied using a planar lipid bilayer technique. The open-state probability and the unitary open-state current both decreased gradually as the Ca$^2+$ concentration was reduced from pCa 3 to pCa 7.5. Each single-channel I-V curve was ohmic at any pCa: the modulating effect of Ca$^2+$ within this range was voltage independent. The Ca$^2+$ dose-response curves for the conductances and open probabilities were all biphasic in shape for both sides of the channel at the voltages used. However, Ca$^2+$ within the pCa ranges used caused significantly more prominent activation of conductance and gating properties on the cytoplasmic side than it did on the SR luminal side. Furthermore, conductance decreased when cytoplasmic Ca$^2+$ concentrations were greater than pCa 3. The I-V relation in this instance exhibited inward rectification caused by a voltage-dependent fast block. This suggests that cardiac SR K$^+$ channel currents may be activated or inhibited through various types of Ca$^2+$ binding sites on and within the channels.

URL: http://dx.doi.org/10.1006/jmcc.1994.1022
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@article{Ueha_1994_195,
  abstract = {The modulating effects of {C}a$^{2+}$ on single {K}$^{+}$ channel
	currents in canine heart sarcoplasmic reticulum were studied using
	a planar lipid bilayer technique. The open-state probability and
	the unitary open-state current both decreased gradually as the {C}a$^{2+}$
	concentration was reduced from pCa 3 to pCa 7.5. Each single-channel
	I-V curve was ohmic at any pCa: the modulating effect of {C}a$^{2+}$
	within this range was voltage independent. The {C}a$^{2+}$ dose-response
	curves for the conductances and open probabilities were all biphasic
	in shape for both sides of the channel at the voltages used. However,
	{C}a$^{2+}$ within the pCa ranges used caused significantly more
	prominent activation of conductance and gating properties on the
	cytoplasmic side than it did on the SR luminal side. Furthermore,
	conductance decreased when cytoplasmic {C}a$^{2+}$ concentrations
	were greater than pCa 3. The I-V relation in this instance exhibited
	inward rectification caused by a voltage-dependent fast block. This
	suggests that cardiac SR {K}$^{+}$ channel currents may be activated
	or inhibited through various types of {C}a$^{2+}$ binding sites on
	and within the channels.},
  added-at = {2009-06-03T11:20:58.000+0200},
  author = {Uehara, A. and Yasukochi, M. and Imanaga, I.},
  biburl = {https://www.bibsonomy.org/bibtex/28fd48ccb166fe844e2b48164ba84fe1b/hake},
  description = {The whole bibliography file I use.},
  file = {Ueha_1994_195.pdf:Ueha_1994_195.pdf:PDF},
  interhash = {3e9c99ac2a5c62a9e9ed107a68e854a3},
  intrahash = {8fd48ccb166fe844e2b48164ba84fe1b},
  journal = {J. Mol. Cell. Cardiol.},
  key = 209,
  keywords = {AMP-Dependent Acid Acid, Acids, Adenosine Algorithms, Alternative Amino Aniline Animal, Animals, Arachidonic Asparagine, Aspartic Bilayers, Binding Binding, Biological Biological, Biotransformation, Cadmium, Calcium Calcium, Carrier Cations, Cattle, Cell Cells, Channel Channels, Chimeric Cloning, Cobalt, Competitive, Compounds, Conductivity, Conserved Cricetulus, Cultured, Cyclic Cysteine, Cytoplasm, Data, Dogs, Dose-Response Drug, Electric Electrophysiology, Enzyme Expression, Extracellular Fibroblasts, Fura-2, Gating, Gene Hamsters, Heart Heart, Humans, Hypoxia, In Inhibitors, Intercellular Ion Junctions, Kidney Kinases, Kinetics, Knockout, Lanthanu, Ligands, Line, Lipid Lithium, Lung, Magnesium, Manganese, Membrane Membrane, Membranes, Mice, Models, Molecular Molecular, Motifs, Potentials, Protein Proteins, Radioisotopes, Relationship, Sequence Sequence, Sites, Space, Splicing, Substitution, Transport, Triphosphate, Tubules, Ventricles, Vitro,},
  month = Feb,
  number = 2,
  pages = {195--202},
  pii = {S0022282884710224},
  pmid = {8006980},
  timestamp = {2009-06-03T11:21:34.000+0200},
  title = {Calcium modulation of single SR potassium channel currents in heart
	muscle.},
  url = {http://dx.doi.org/10.1006/jmcc.1994.1022},
  volume = 26,
  year = 1994
}

%0 Journal Article
%1 Ueha_1994_195
%A Uehara, A.
%A Yasukochi, M.
%A Imanaga, I.
%D 1994
%J J. Mol. Cell. Cardiol.
%K AMP-Dependent Acid Acid, Acids, Adenosine Algorithms, Alternative Amino Aniline Animal, Animals, Arachidonic Asparagine, Aspartic Bilayers, Binding Binding, Biological Biological, Biotransformation, Cadmium, Calcium Calcium, Carrier Cations, Cattle, Cell Cells, Channel Channels, Chimeric Cloning, Cobalt, Competitive, Compounds, Conductivity, Conserved Cricetulus, Cultured, Cyclic Cysteine, Cytoplasm, Data, Dogs, Dose-Response Drug, Electric Electrophysiology, Enzyme Expression, Extracellular Fibroblasts, Fura-2, Gating, Gene Hamsters, Heart Heart, Humans, Hypoxia, In Inhibitors, Intercellular Ion Junctions, Kidney Kinases, Kinetics, Knockout, Lanthanu, Ligands, Line, Lipid Lithium, Lung, Magnesium, Manganese, Membrane Membrane, Membranes, Mice, Models, Molecular Molecular, Motifs, Potentials, Protein Proteins, Radioisotopes, Relationship, Sequence Sequence, Sites, Space, Splicing, Substitution, Transport, Triphosphate, Tubules, Ventricles, Vitro,
%N 2
%P 195--202
%T Calcium modulation of single SR potassium channel currents in heart
	muscle.
%U http://dx.doi.org/10.1006/jmcc.1994.1022
%V 26
%X The modulating effects of Ca$^2+$ on single K$^+$ channel
	currents in canine heart sarcoplasmic reticulum were studied using
	a planar lipid bilayer technique. The open-state probability and
	the unitary open-state current both decreased gradually as the Ca$^2+$
	concentration was reduced from pCa 3 to pCa 7.5. Each single-channel
	I-V curve was ohmic at any pCa: the modulating effect of Ca$^2+$
	within this range was voltage independent. The Ca$^2+$ dose-response
	curves for the conductances and open probabilities were all biphasic
	in shape for both sides of the channel at the voltages used. However,
	Ca$^2+$ within the pCa ranges used caused significantly more
	prominent activation of conductance and gating properties on the
	cytoplasmic side than it did on the SR luminal side. Furthermore,
	conductance decreased when cytoplasmic Ca$^2+$ concentrations
	were greater than pCa 3. The I-V relation in this instance exhibited
	inward rectification caused by a voltage-dependent fast block. This
	suggests that cardiac SR K$^+$ channel currents may be activated
	or inhibited through various types of Ca$^2+$ binding sites on
	and within the channels.

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Calcium modulation of single SR potassium channel currents in heart muscle.
A. Uehara, M. Yasukochi, and I. Imanaga.
J. Mol. Cell. Cardiol. 26 (2): 195--202 (February 1994)

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BibSonomy

Calcium modulation of single SR potassium channel currents in heart muscle.A. Uehara, M. Yasukochi, and I. Imanaga. J. Mol. Cell. Cardiol. 26 (2): 195--202 (February 1994)

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Comments and Reviews

Cite this publication

Calcium modulation of single SR potassium channel currents in heart muscle.
A. Uehara, M. Yasukochi, and I. Imanaga.
J. Mol. Cell. Cardiol. 26 (2): 195--202 (February 1994)